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Audio Drops/Loops Between Two Endpoints

Ed Chiodo
Occasional Visitor

Audio Drops/Loops Between Two Endpoints

Hello All,


My first post in the Polycom Community forums, so I apologize in advance for any shortcomings in this post!


I currently have two endpoints, a RealPresence Group 500 (running release in Boston, and an HDX 7000 (running release 3.1.4-43132) in New York.  The two sites are connected via an IPsec tunnel (a Cisco ASA 5505 in Boston, and a Cisco ASA 5510 in New York, both running current IOS releases) that passes all IP traffic.  Both sites have a 100Mbps upload and 100Mbps download fiber connection to the public Internet.


When I initiate a call between the codecs using h323, the calls connect without issue.  The first 5 or so minutes I have no probles with audio, video, or content.  Roughly 5 to 10 minutes into the call, New York is no longer able to hear audio from the Boston site, as it either cuts out entirely or loops the last second or so of audio.  However video and content continue to function normally.


My initial thought was that it was a speaker problem in New York, but a speaker test proved this was not the case.  My focus then turned to the microphones in Boston, but after swapping out several Polycom microphone arrays as well as microphone cables, I determined this was not the case either.  A quick look at the audio meters confirms that Boston is indeed picking up audio correctly.


I then turned to my network to see if it was the root of the issue.  A simple ping test run over a 24 hour period shows latency/loss are minimal, with 0% packet loss and an average latency of 29 ms.  Fixup for h323 h225 and h323 ras is disabled on both Cisco ASAs.  I then ran 2 tests, I had a laptop running Polycom RealPresence Desktop in New York call the RealPresence Group 500 in Boston, and a laptop running Polycom RealPresence Desktop in Boston call the HDX 7000 in New York.  Neither call experienced any issues.  I thought it might be an issue with the codec's connections to the switches, but a simple "show interface gig x/x/x" shows 0 runts, 0 giants, 0 throttles, 0 input errors, 0 CRC, 0 frame, 0 overrun, and 0 ignored for both endpoints.


After consulting with my Polycom Support partner, they thought the correct course of action would be to RMA the RPG 500 in Boston, but the problem persists after the replacement was installed.  Getting more desperate, I turned to the HDX 7000 and performed a factory reset, again to no avail.


Having ruled out the speakers, microphones, RPG 500 hardware/config, HDX 7000 config, and (to some extent) the network, I'm stuck!  Does anyone have insight as to what I can do to troubleshoot further?


Appreciate the time you took reading my essay!



Message 1 of 7
Respected Contributor

Re: Audio Drops/Loops Between Two Endpoints

Hello Ed


Some days ago in the Community was a post with the same problem.

It might be a software problem.

You should raise a service request in the Polycom support directly or via your Polycom reseller.


but also you  can try to install a previous version of Group (or HDX) software, start downgrade from Group, because you and MSCS both are using the latest software on Group codecs.




Message 2 of 7
Ed Chiodo
Occasional Visitor

Re: Audio Drops/Loops Between Two Endpoints

Thank you Bazzuck!


Striking similarties between MSCS's post and my own, I'll reach out to him and see if there are any other commonalities in our setups.


Raised a service request with my reseller, hopefully they can get back to me soon and take a deep dive.


I am fairly convinced this is an issue with the site to site IPSec tunnel between our Cisco ASAs, but it is very frustrating that I can't pinpoint the problem.  As soon as I work with my reseller and possibly Cisco I'll report back, maybe I can save someone else a few headaches.




Message 3 of 7
Polycom Employee & Community Manager

Re: Audio Drops/Loops Between Two Endpoints

Hello Ed,

welcome to the Polycom Community.

The HDX and I believe the GroupSeries in standard mode use a wider range of Ports for the Audio and Video that the RPD Software.


You can set it to fixed ports and try this again?

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

The title Poly Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.


Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 4 of 7
Respected Contributor

Re: Audio Drops/Loops Between Two Endpoints

Hi Ed

Just for test, enable a Basic Mode on HDX (or Group) and try to make a call again.

Go to HDX Menu > Admin Settings > Network > Call Preference > Select Enable Basic Mode
Message 5 of 7
Ed Chiodo
Occasional Visitor

Re: Audio Drops/Loops Between Two Endpoints

Thank you Steffen and Bazzuck,


I'll try both of your suggestions and let you know my findings.


Now to add a bit of fuel to the fire, the same problem is occuring on a new RealPresence Group 500 (running release 4.1.1-60400) in our San Francisco branch when calling the same HDX 7000 in New York.  Again, these two are connected by a site to site IPSec tunnel (Cisco ASA 5505 in San Francisco running a current release, ASA 5510 in New York running a current release)  allowing all IP traffic, and both have fixup for h323 h224 and h323 RAS disabled.


This leads me to believe the problem is with the site to site tunnels, or with the HDX 7000.


I've opened a Cisco TAC case, and am working with my Polycom reseller now.  If the fixed ports option does the trick I'll let you all know.  I'll also report back on my findings after making a call with Basic Mode (now called Diagnostic Mode).


Appreciate all of your input!


Message 6 of 7
Occasional Advisor

Re: Audio Drops/Loops Between Two Endpoints

FYI   I also came to the same conclusion with my setup that it is a problem with the HDX 7000 or the IPSEC tunnel.   Disabling the h.323 helper on our Fortigate did not change anything.   Will be following up with Polycom and Fortinet.

Message 7 of 7